Impious

Ok? Since I don't see a question actually posed on your post, I'm going to assume you would like us to help you decide which to purchase. However, your post does not contain enough information for us to really be of much aid. For starters, it would be very helpful to know what subwoofers you were using and what your electrical system will consist of.

I guess I really don't understand what this thread is about? Are you asking a question or just making random statements?

He is THE ONE. . . . LOL.....Well played Ryan.

The "back plate" part is 25mm thick -- and is needed for the amount of flux intended for the design. 35mm of the plate is cut out for clearance which leaves a good bit of room so I can use a range of coil lengths. With a 50mm long coil I have 37.5mm of clearance remaining, for example. I didn't want to have a multi-piece assembly so I had it all milled out from a solid chunk of steel... back plate and pole are all one piece. Cool beans. I was just curious......looked like a whole lot of steel back there

Keep in mind that most high volume manufacturers design their equipment for a wide range of uses. While the unit may clip at 75-80% of maximum volume with a 0db tone, it won't with a lower level source......which gives the HU some additional "headroom" in it's volume range when used with lower level sources, such as radio or quieter music. So just because a HU clips at less than full volume, it doesn't make it "bad", just designed for a different range of consumer uses. Asking the question "does this headunit clip" to a manufacturer is a little vague.....it all depends on the various setting and source material. That's like asking an amplifier manufacturer if their amps clip the signal.....sure they can, they all can, it's just a matter of when and why, or under what circumstances. Just like with an amp, different settings (such as boosting the treble or bass controls, or EQ bands if the HU has them) will cause the unit to clip earlier in it's volume range (or cause a unit that doesn't "clip" with a 0db tone to start clipping the outputs). And as mentioned......no, not all HU's clip at a given volume setting. But they all can, depending on the use.

By the 4th layer you are gaining little to no benefit by way of constrained layer damping and basically just adding mass to the panel.....in which case, there are possibly cheaper and more effective means of simply adding mass. Hence my comment. As to the original question; If flexing the door panel is the problem, is there a means by which you could seal off the inner door panel so that less pressure is reaching the exterior door panel? I think that may be a better option than trying to re-engineer the door structure. You may even by able to incorporate some form of bracing the exterior door panel into the system.

What's up with the ginormous backplate? Just from looking at the pictures it doesn't look like it needs all of that simply for rearward clearances.......is the large backplate required to carry the full magnetic flux of the motor without oversaturating?

I know I've mentioned this before, and I believe it might have even been the last time you posted that particular picture. The KLM wire is CCA (copper clad aluminum). Stinger is true copper AFAIK. The aluminum wire has to be thicker to have similar performance to true copper cable (the Stinger, in this example). So it's not "OMG look the Knu is so much thicker"........if the KLM wasn't thicker, then it wouldn't have performance close to that of 4ga actual copper wire. It's not thicker because it's better; it's thicker because if it wasn't, it would be substantially worse. The KLM being thicker only makes it closer in performance to actual copper, not better because it's thicker. The KLM is thicker because it has to be, because it's made with an inferior material. I believe even with the oversized thickness, the CCA wire still has less capabilities than accurately sized copper wire. And as mentioned above by 95Honda, strand count only affects flexibility. I believe Duran's point was that a fancy name on the jacket doesn't make the cable better. As long as the thickness is correct for the gauge, the strand count is high enough to have the flexibility you need, and it's copper, it will perform just as well regardless of the brand name.

Somewhere between office background noise and a space shuttle launch.

Tell me more about the setup. What mids are you using, how many, where are they being located, what exactly is it you are trying to brace? I wouldn't do 4 layers of deadener. Each additional layer is progressively less effective. By the 4th layer you are wasting a lot of time and money for little benefit.

As noted, the graph was generated with the Klippel measurement system.

As long as it's not the cheap fleabay wire that is really only 4ga or 8ga even though the jacket is stamped 0/1ga.......welding wire is fine.

Good luck with the project Now that you've spilled the beans on your project, feel free to post results and progress here on SSA as well if you don't mind and have the time I for one would be interested in seeing what you are able to come up with.

A pair of those drivers would do very well IB in a vehicle.

No product on earth has a failure rate of 0%. Every product is going to have some percentage of units that fail. You purchased from an unauthorized dealer to save $25. The trade-off is that if the unit fails, you are SOL on a replacement or warranty. That is the risk you accepted when you decided to purchase from an unauthorized dealer; You accepted that not having a warranty on the product was worth the $25 initial savings when you purchased the product. There is absolutely no sense in blaming the product or company for your decision. PAC can't track the history of that unit because it was purchase unauthorized.......It might have been a B-stock, non-authorized repair, used or malfunctioning unit that the "dealer" tossed on ebay to make some easy money. It happens, and that's the reason PAC won't warranty those products. You have nobody to blame but yourself. It's a "funkin' joke" that you are blaming PAC because you made a decision and accepted risks that ended up biting you in the ass.

Well, I don't know how helpful this may be, but worth a shot. Fi X 12" Fs is already almost 36hz, from some quick figuring it looks like mass would only need to drop by ~27g to reach an Fs of ~39hz. Now, I don't know the mass of their dustcaps, but you are starting from a much closer point so that might be something they may be able to help manipulate with the dust cap. Q is higher, but they have a S2 and S4 options, so they may be able to manipulate the coil and gap width/etc to lower the Q to your target. Vas is smaller than the Dcon which from the sounds of things, if you can get the Fs and Q within your target range the smaller Vas will help keep overall size down some. 18mm Xmax will help reach your output goals. And it's still an affordable driver I would shoot Scott or Nick @ Fi an email or PM on here and see if that's something they could work out for you. As a last ditch effort, you may try the Audioque HDC. It's twice as expensive, but the Fs and Q are already in your range and it should have enough useable throw for your application. Oh, or a Fi BL.....again, expensive (compared to your goal), but the dual 2 has an Fs and Q that should be within your range, good throw and small Vas. Pro Audio drivers would be nice for your app, but it's hard to find an affordable driver that has significant throw

I can't imagine a dust cap change would be enough of a drop in mass to increase Fs to the range you need for this driver. It appears, on a Dcon, you would need to decrease the mass by about half to get the Fs into the range you need. Which means the most logical option would be to decrease the compliance of the suspension. Would the raise in Q and decrease in Vas as a result still be acceptable to your design goals?

POWER : 1970 Watts AMP VOLTAGE (measured) : 49.25 V AMP CURRENT (calculated) : 40 A ACTUAL IMPEDANCE (calculated) : 1.23 ohms SUPPLY VOLTAGE : 12.85 V bump the voltage up a little an this beast could 800 over the rated 1500 I'm sure.... improbable but not impossible... Those numbers are even more worthless than the numbers listed on birthsheets. I really wish people would stop quoting "clamped" power. Those numbers are useless to the average user, and in no way are relevant or related to rated power. Ignore them. Forget you ever read them. They're useless, pointless, irrelevant, meaningless. And stop comparing them to "rated power".....they are not comparable!

I think that's fairly fitting and indicative of the attitude you've taken during your tenure as owner of Second Skin. I'm glad to see you'll no longer be formally associated with the company. I'm going to guess the various car audio forums you own were the beginnings of your "media empire", it's unfortunate that you won't be exiting those as well. By the way, I seem to recall you stated in a (now deleted) thread on CA.com that the company wasn't for sale, until someone posted a link, then you vanished from that conversation. Interesting. Good riddance. Hey, maybe we could even look into adding a subforum for another deadening company on SSA now as well!

I would agree with Sean that trying to use the 12" with a tweeter in a 2-way in an automobile is probably a bad idea. I would stick with a 3-way front stage and add a tweeter to cover to top few octaves if necessary.

I don't know anyone with any intelligence that would make such a recommendation. The size of the sub has nothing to do with overpowering your front stage, and there are distinct advantages to using large diameter subs.

You keep asking about subwoofers, but you've yet to tell us what your actual goals and objectives are for the system. What are you trying to accomplish? Are you focused more on sound quality or output?

has anyone heard anything about planet audio's big bang 2 series of subwoofers? the 12" has an efficiency of 95db at 1W/1M No they don't. That's called marketing. Link: Sensitivity Sensitivity (SPL) = 112 + 10*Log(9.64 * 10^(-10) * Fs^3 * Vas / Qes) SPL = 112 + 10 * LOG(9.64 * 10^(-10) * 29^3 * 39.64 / 0.586) = 84db So the actual sensitivity of the driver is a full 11db lower than advertised at 84db.

Excellent choice on subwoofer. The Gti units are solid performers. If they weren't so deep I'd probably be running one myself. As for measurements, sounds like you have the jist of things for EQ. If you want to do MLS measurements you'll need a preamp source as well.....the sound card in your computer might work if the response is reasonably flat and it has fixed timing. But for just EQ all you need is the mic and preamp. The forums on DIYMA have had a lot of good discussions and information on measuring the system. I'd suggest some searching over there when the time comes to get down to business.

0db eliminates the possibility of clipping, but as you noted results in the lowest amount of average power output. Richard Clark and many others have long suggested a -10db test tone to maximize average power output while keeping clipping at reasonable levels. This may be a little on the high side for someone who may be overpowering their drivers or are unable to recognize driver stress. -6db may be a little safer for those folk.